SAN FRANCISCO — District Attorney George Gascón said today the U.S. Department of Justice will take over his office’s independent investigation into allegations that San Francisco police illegally searched rooms at a residential hotel.

After new information came to light in the investigation this morning, Gascón said, he spoke with U.S. Attorney Melinda Haag, who agreed to take on the investigation. The criminal probe stems from allegations of police misconduct at the Henry Hotel, where cops allegedly made drug arrests after using master keys to conduct warrantless searches of residences there. The investigation appeared to widen this week after Public Defender Jeff Adachi publicized more cases at other single-room occupancy hotels where cops allegedly entered residences illegally.